[PATCH] hw/block/nvme: drain namespaces on sq deletion

[Klaus Jensen <its@irrelevant.dk>]

From: Klaus Jensen <k.jensen@samsung.com>

For most commands, when issuing an AIO, the BlockAIOCB is stored in the
NvmeRequest aiocb pointer when the AIO is issued. The purpose of storing
this is to allow the AIO to be cancelled when deleting submission
queues (it is currently not used for Abort).

Since the addition of the Dataset Management command and Zoned
Namespaces, NvmeRequests may involve more than one AIO and the AIOs are
issued without saving a reference to the BlockAIOCB. This is a problem
since nvme_del_sq will attempt to cancel outstanding AIOs, potentially
with an invalid BlockAIOCB.

Fix this by instead of explicitly cancelling the requests, just allow
the AIOs to complete by draining the namespace blockdevs.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
---
 hw/block/nvme.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 316858fd8adf..91f6fb6da1e2 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -403,6 +403,7 @@ static void nvme_req_clear(NvmeRequest *req)
 {
     req->ns = NULL;
     req->opaque = NULL;
+    req->aiocb = NULL;
     memset(&req->cqe, 0x0, sizeof(req->cqe));
     req->status = NVME_SUCCESS;
 }
@@ -2396,6 +2397,7 @@ static uint16_t nvme_del_sq(NvmeCtrl *n, NvmeRequest *req)
     NvmeSQueue *sq;
     NvmeCQueue *cq;
     uint16_t qid = le16_to_cpu(c->qid);
+    int i;
 
     if (unlikely(!qid || nvme_check_sqid(n, qid))) {
         trace_pci_nvme_err_invalid_del_sq(qid);
@@ -2404,12 +2406,18 @@ static uint16_t nvme_del_sq(NvmeCtrl *n, NvmeRequest *req)
 
     trace_pci_nvme_del_sq(qid);
 
-    sq = n->sq[qid];
-    while (!QTAILQ_EMPTY(&sq->out_req_list)) {
-        r = QTAILQ_FIRST(&sq->out_req_list);
-        assert(r->aiocb);
-        blk_aio_cancel(r->aiocb);
+    for (i = 1; i <= n->num_namespaces; i++) {
+        NvmeNamespace *ns = nvme_ns(n, i);
+        if (!ns) {
+            continue;
+        }
+
+        nvme_ns_drain(ns);
     }
+
+    sq = n->sq[qid];
+    assert(QTAILQ_EMPTY(&sq->out_req_list));
+
     if (!nvme_check_cqid(n, sq->cqid)) {
         cq = n->cq[sq->cqid];
         QTAILQ_REMOVE(&cq->sq_list, sq, entry);
-- 
2.30.0